Reiko? REIKO?!?!?!? AAAAAAAAAAAFHGHDHGDGHHdhgdh. I'm okay with the twist in the sense of it being "9-3's teacher was the extra person rather than a student". In fact, I had considered that this very thing was going to be the ultimate twist, however after Kubodera killed himself I didn't begin to suspect Ms. Mikami. Still, just so I don't make an ass of myself, the fact that Ms. Mikami and Reiko were the same person was the other part of the twist, right? I'd hate to think that it had been immediately established that they were the same person and I had somehow missed this.
If it WAS part of the twist, though, it was an incredibly silly thing to hide from the viewer for the entire series. All of that deception just for a few moments of extra anguish from Kouichi over having to kill his aunt? I would have been just as satisfied if the extra person had been Ms. Mikami and a separate person from Reiko.
Well, on the whole, the series didn't end nearly as tightly as I would have liked. I was expecting the death phenomenon to have some kind of connection to Yomiyama Misaki's death deeper than "it started happening after he died". Because there was never any dirty secret or foul play behind the death, it never made any sense for Misaki's death to result in such a terrible, grudging curse against Class 9-3. I had originally expected the show to have a heavy focus on Kouichi and Mei investigating the true nature of Misaki's death and bringing about an end to the phenomenon from the information they uncover. The show certainly opened strongly, but as several other people have complained, it discarded its own identity and just became Final Destination by the end. It was never a bad show, but it failed to realize its potential.